The primary objective of this project is to field test a diary technique for monitoring individuals' cancer-related health practices. It is therefore a Phase I study in the sequence of cancer prevention and control research. A total of 240 men and women, aged 50 and over, will be recruited through a Family Care outpatient clinic, and randomly assigned to one of six groups (each n = 40). These groups are designed to assess reliability of diary data over two weeks (Groups 1 and 2), stability over two months (Groups 3 and 4), and correspondence between interview-based based verbal reports and the diary (Groups 5 and 6). A possible reactive effect on health practices will also be examined. The diary will be kept on a daily basis, for a two week period. A predetermined set of questions will be answered each day, representing the areas of smoking and smokeless tobacco use; tendency to include fat and nitrates in the diet; fiber, vegetable and fruit in the diet; occupational safety practices; passive smoke exposure; and alcohol intake. This investigation is directed toward the long-range hypothesis that a decrease in, and then the sustained maintenance of, lowered cancer incidence and case- fatality rates in the population depend upon achieving (and maintaining) a desirable behavioral pattern across multiple cancer-related practices. The use of a diary method also allows asking new questions about "at-risk" status for cancer, based upon the consistency observed in health practices, and how cancer- related practices fit into the individuals's overall profile of preventive behavior.